1. Field of the Invention
The present invention relates to a solid-state imaging device configured by mounting an imaging element such as a CCD on a substrate and a method for producing the same.
2. Related Background Art
Solid-state imaging devices are used widely for video cameras and still cameras, and are provided in a form of a package in which an imaging element such as a CCD is mounted on a base made of an insulating material and a light-receptive region is covered with a transparent plate. In order to miniaturize the device, the imaging element is mounted on the base while maintaining a bare chip state. As a conventional example of such a solid-state imaging device, a solid-state imaging device described in JP 5(1993)-267629 A will be described below with reference to FIG. 7.
In FIG. 7, reference numeral 21 denotes a base. On a top face of the base, a recess is formed, and an imaging element chip 22 is fixed at a center of the recess. The base 21 is provided with a lead terminal 24, and a lead pad 25 of the lead terminal 24 and a bonding pad 23 on the imaging element chip 22 are connected via a bonding wire 26 made of a metal wire. On an outer peripheral portion of the top face of the base 21, a rib 28 is provided, and a light transmissive seal glass plate 27 is fixed thereon, so as to form a package for protecting the imaging element chip 22.
Such a solid-state imaging device is mounted on a circuit board, in such a position as shown in the drawing, with a seal glass plate 27 side facing upward, and the lead terminal 24 is used for the connection with an electrode on the circuit board. A lens barrel (not illustrated) with an imaging optical system incorporated therein is provided above the seal glass plate 27, where a relative positional relationship with a photo-receptive region formed in the imaging element chip 22 is set with predetermined accuracy. During the imaging operation, by means of the imaging optical system incorporated in the lens barrel, light from an object to be imaged is collected onto the light-receptive region so as to effect photoelectric conversion.
The above-described conventional solid-state imaging device has a configuration in which the lead terminal 24 is arranged at a side face of the base 21, and therefore the process of manufacturing the same becomes complicated and the miniaturization of the package becomes difficult.
In addition, due to the presence of the lead terminal 24, a side face of the package formed with an end face of the base 21, a side face of the rib 28 and an end face of the seal glass plate 27 is not flat. If the side face of the package is flat, at the time of mounting the lens barrel with the optical system included therein, the position of the lens barrel can be determined easily and with high precision by utilizing the side face of the package. That is to say, the position in the horizontal direction can be determined by bringing the side face of the package into contact with an internal face of the lens barrel, whereas the position in the vertical direction can be determined by bringing a bottom face of the lens barrel into contact with the circuit board face. On the other hand, if the side face of the package is not flat, it becomes difficult to determine the position with high precision by the above-described positioning method.